What are the symptoms of altitude decompression sickness (DCS)?

Altitude decompression sickness (DCS), commonly referred to as "the bends," primarily manifests through symptoms such as joint pain and respiratory distress. This condition occurs when a person ascends to a high altitude too quickly, causing nitrogen bubbles to form in the body due to changes in pressure. These bubbles can accumulate in the joints, leading to significant pain, often described as a deep, nagging ache similar to that experienced in arthritis.

In addition to joint pain, individuals may experience respiratory distress; nitrogen bubbles can affect the lungs, leading to coughing, difficulty breathing, and chest pain. These symptoms are critical indicators that require immediate medical attention, as the effects of DCS can worsen without prompt treatment.

The other choices highlight symptoms that, while associated with various conditions or flying at altitude, are not the hallmark signs of altitude DCS. Headaches and nausea may occur for other reasons such as altitude sickness (acute mountain sickness). Vision impairment and dizziness are often symptoms linked to various other hypoxic conditions and not specific to DCS. Fainting and loss of balance could be symptoms related to numerous medical issues or hypoxia, but they are not specific indicators of DCS.